LowGlider, I come from your area (Eastcote) although I haven't lived there for 40 years. I learnt to fly at Booker and later instructed at Elstree. I have to say that both were very easy to access. However, a recommendation from 46 years ago will not hold much weight methinks!!
What I do want to say is that I echo previous posts on the frequency of the flying lessons - the more frequent the better the progress. But don't be disheartened if you can't do more than a couple a month - I simply couldn't afford to do otherwise in 1969/70 (sometimes even less frequently) and I managed to qualify ok - and have been earning my living flying aeroplanes since 1973. As someone said, you may occasionally take a step forward and two back.
Enjoy! I do hope you are aware that you are highly likely to set up a pattern in your mind which will be impossible to ignore. The Flying Bug. Nearly half a century on, it hasn't left me!